In logic and critical thinking, there are different types of cognitive biases and ways of faulty reasoning that lead to erroneous conclusions. Logicians refer to these as “fallacies.”

One of the more common types is known as “poisoning the well.” Essentially, when one is biased against another person (for whatever reason), they will convince themselves and others around them that anything the other person says in a discussion is fundamentally flawed because it is coming from a person with a flawed character (Walton, 1998). In other words, one is saying, don’t listen to that person, they are XXX (insert perceived character flaw), so anything they say isn’t logical, sound, or correct.

The reason this type of “reasoning” is a fallacy is that it, like other fallacies, operates on the basis of little or no evidence. As such, it is prone to yield erroneous conclusions because it is not an orderly, objective way to reason through an argument.

It sounds a lot like a prejudice, doesn’t it? Prejudice is a negative feeling toward someone based on their membership (or perceived membership) in a group. So, for example, if you were talking about parenting your children with someone you just met, and found out that the person is childless, you might immediately be very dismissive of any parenting advice that person offers due to their childless status. How can that person possibly have useful information about child rearing if they haven’t lived the experience of parenting?

The same might apply to a patient in alcohol or drug rehab who encounters a therapist who has never had any alcohol or drugs themselves. The patient might think, “There is no way this person will ever truly understand what it is like to be an addict—therefore, I am not going to listen to anything they have to say.”

Now that may be true—but let’s say that the counselor did have addiction problems in the past. That doesn’t mean they would automatically “completely understand” the patient’s unique history and thoughts, feelings, or experiences with regard to their own struggles with addiction. However, it would be illogical to negate—by poisoning the well—all of the counselor’s experience with many different counseling sessions of patients with addiction, coupled with their formal therapy training and academic background.

Which brings us to the research focus of this post. McClure, Pitpitan, and Quinn (2023) recently published the results of their studies on how patients would perceive and react to medical advice from overweight healthcare providers. Results showed that patients had a more negative view of these providers, and they were less likely to follow the medical advice of these providers, especially in the area of weight-related advice or information. Both men and women reacted this way to the overweight health providers.

In addition to contributing to the bias against overweight people in our society, these types of pre-judgments (prejudices) in the area of weight-related medical advice are precisely the types of poisoning-the-well fallacies discussed here. The patients are saying to themselves, “Because that person is overweight, I can’t trust any information or medical advice they give me regarding weight.”

In addition to representing faulty thinking, poisoning the well fallacies can result in real physical harm, as in these cases. When a patient ignores the experience and medical knowledge the healthcare person offers, the patient is potentially putting their own health in jeopardy.

When people are informed about bystander apathy (the phenomenon in which the more people witness someone needing help, the less likely any of them will help), they are more likely to help others in the future (McMahon et al., 2021). When people learn about the ways we are prejudiced, they often (but not always) will be more open-minded to thinking in a more egalitarian way about others (Nelson & Olson, 2023).

Hopefully, after our short discussion about the ways that cognitive fallacies such as “poisoning the well” result in negative, inaccurate views of others, and can hurt ourselves, perhaps you might be more willing to think differently about others going forward. You certainly wouldn’t want others to dismiss everything about you out of hand due to some perception they had of you, right? Similarly, you shouldn’t dismiss others due to some prejudged perceived “flaw.” It’s not smart. It’s uncivil, and it’s illogical.